Force 85 Backfire & stalls in gear

[eagle787]

Force, 856F7B, 1987
idles in neutral OK, but with a slight exhaust backfire
and when in gear trying to accelerate motor bogs down/stalls.
Motor will start up again, but same thing happens, as soon as I slip it into FWD/REV gear it stalls.
Any help would be appreciated. Thanks

 

[87Force85]

Eagle787, I have the exact same outboard Force, 856F7B, 1987, and I'm having a similar problem. Have you checked for spark on all three cylinders? I checked mine and found only weak spark on all three. The engine starts and runs, but poorly and passes unburned fuel out the exhaust. Based on the troubleshooter on outboardignition.com I'm going to check for loose/broken wires first.

I wanted to have a professional look at mine, but no one will look at it because its too old!

 

[eagle787]

Spark is visually good on all 3. Have not yet used a gap checker. Good idea you have to go through all the wires/grounds ect..

 

[eagle787]

I think I will start by making sure my air/mix screw is at about 1 turn full out, maybe a little more (all 3 carb) Then hook up TACH get the idle up....see what happens. maybe I'll spray some carb cleaner through air/mix hole when needle screw is out Don't realy know to much about outboards

 

[87Force85]

I did all those things with mine and ran some seafoam in the gas, all out of the water with the muffs on. Then I put it in the lake riding a wave of confidence and it had a lot of trouble starting and bogged down and died at higher speeds. The bottom carb screw is hard to get at, I read on here somewhere that there's a small hole in the cowling beneath the weather seal that you can get a small screwdriver through... so look for that.

 

[jerryjerry05]

The backfire at idle: reset the air screws 1 turn out, factory setting.
That help? no then get a can of starting fluid.
Start motor, spray the SF around the intake side, around the port covers and
under the ignition components, and the base of the carbs.
That make it run different? then you have a bad gasket or loose carb or bad fuel pump.

One tiny cough or backfire can blow the port cover gasket/ gaskets.
If you replace? use a sealer/silicone and let it cure before using.

Any fuel coming from the front of the carb/s possible bad reed?

 

[eagle787]

I will work on outboard this weekend/possibly sooner? and get back tp post results. Hopefully backfire did not blow port cover. thanks

 

[eagle787]

I have not noticed fuel coming out of rear carb's...I'm thinking like your saying to set the Air/mix screws and should take care of backfire & hopefully give me more power so it won't stall in gear.

 

[eagle787]

jerryjerry05 Which spark plug would you recommend? for the: Force, 856F7B, 1987

 

[jerryjerry05]

UL-18V
Or the NGK
Both work good.

Some people say the NGK is the better plug, I never saw any difference.

 

[eagle787]

Thanks for the info..I'll let you know how it's running in a day or 2.. appreciate it

 

[eagle787]

I removed and inspected and reinstalled the idle air mixture screws lightly seated one turn out on all three carbs, started motor while it's idling I noticed fuel was leaking from the carburetors throat, on all three. Leaking right out the front of carbs. pretty good amount had it idling for maybe five minutes and there was a pretty good puddle of fuel on the bottom cowl. Should I check the Reed valves? Any help would be greatly appreciated. Thank you.

 

[jerryjerry05]

Floats on all 3 ??
Check the fuel pumps diaphragm.

 

[eagle787]

Will do, thanks..I'll get back with results thanks

 

[eagle787]

Hi all, I am having trouble finding the correct Walbro carb rebuild kit. Can someone please help me find the correct
KIT number & WEB Site to place order please? I also need complete gasket kit, not sure if ALL gaskets would come with kit. Or maybe should i just make my own gaskets?? Or the replacement after market number & complete gasket kit. I am waiting to remove carb's until I have the rebuild kits. Here's the INFO:
1987 Force (US Marine) 85, 856F7B carburetor has these #'s stamped on flange
WE-18-1 (Top Carb) WE-18-2 (Center & Bottom Carb)
& 632061-1 on the opposite flange, same # on all 3.

WE-18 to order or the 632061-1 I tried using both and I'm just don't 100% confident that it's going to be the correct kit, so i have not ordered anything yet...Hopefully someone has used a certine web site and ordered the WE 18 seris and can send me that info.. I have watched a lot of YouTube videos where the guy orders the WRONG carb kit... any help on this would be greatly appreciated. thanks.

 

[eagle787]

Also I forgot to mention that when i was working on the Idle air/MIX screws they where all set at about 3/4 turn out, maybe slighty more than 3/4. They are now at 1 turn out.

 

[eagle787]

[No message]

 

[eagle787]

pics of the carb flange numbers